D defs.my
Entry 1 sense Webster, 1913

Pentacid

· Pen·tac·id · IPA
01 a. Capable of neutralizing, or combining with, five molecules of a monobasic acid; having five hydrogen atoms capable of substitution by acid …
  1. 1.
    Capable of neutralizing, or combining with, five molecules of a monobasic acid; having five hydrogen atoms capable of substitution by acid residues; -- said of certain complex bases.(Chem.)